Dear Hossain.

Sure, they are different. Here some popular protocols:

For gDNA: https://www.ncbi.nlm.nih.gov/m/pubmed/21476197/

For cDNA:

https://www.thermofisher.com/hk/en/home/references/protocols/nucleic-acid-amplification-and-expression-profiling/cdna-protocol.html

For rDNA:

https://scholar.google.com.co/scholar?q=ribosomal+dna+protocol&hl=es&as_sdt=0&as_vis=1&oi=scholart#d=gs_qabs&p=&u=%23p%3DdFNlY6r6-0IJ

Best regards